This application is related to imaging and treatment methods for a body. In particular, it relates to an imaging and treatment method which employs trimetallic nitride template endohedral metallofullerene compounds.
Endohedral metallofullerenes are fullerene structures (carbon clusters) with closed topologies, encapsulating metallic or non-metallic atoms. Typically, metallofullerenes are prepared by impregnating graphite rods with a metal salt and annealing at approximately 1000xc2x0 C. Before the rods bum, a small amount of metallofullerene is produced in the soot. The soot is then extracted with solvents such as CS2 or o-dichlorobenzene, followed by high performance liquid chromatography (HPLC) to obtain pure samples of the endohedral metallofullerenes. M@C82 is the most predominant species extracted. However, multiple metal-atom species such as Y, Ho, or Er dimers, and Sc trimer have also be formed and extracted. Although a broad range of endohedral species containing from 60 to 200 carbon atoms and one or more metal atoms have been formed, most are insoluble and, thus, are not useful for biological applications. Typical metal atoms that are encapsulated are alkali metal, alkaline earth metal, Sc, Y, U or a lanthanide metal. The lanthanide elements have been found to be useful for diagnostic and therapeutic medicine, making them attractive for applications in medicine.
Current synthesis methods make it difficult to perform detailed studies of the properties associated with endohedral metallofullerenes because the typical yields are less than 0.5%. In addition, multiple endohedral fullerene isomers are produced using these synthetic methods.
Stevenson et al. (xe2x80x9cSmall-bandgap endohedral metallofullerenes in high yield and purity,xe2x80x9d Nature, Sep. 2, 1999, Vol. 401, pp. 55-57) describe a technique where the introduction of small amounts of nitrogen into an electric-arc reactor allows for the efficient production of a new family of stable endohedral fullerenes encapsulating trimetallic nitride clusters, Er2xe2x80x94SC3xe2x80x94N@C80 (x=0-3). The trimetallic nitride template process generates milligram quantities of product containing 3-5% Sc3N@C80, allowing isolation of the material and determination of the crystal structure, optical and electronic properties. The Sc3N moiety is encapsulated in a highly symmetric, icosahedral C80 cage, which is stabilized as a result of charge transfer between the nitride cluster and the fullerene cage. Their method provides access to a range of small-bandgap fullerene materials whose electronic properties can be tuned by encapsulating nitride clusters containing different metals and metal mixtures. Although Stevenson et al. have described a new type of endohedral metallofullerene that contains anywhere from 0-3 atoms, they fail to provide a specific use for these materials. Moreover, since the atoms contained within the fullerene cage are all the same, the versatility of the compounds is greatly restricted.
An object of the present invention is to provide a method for imaging and treating an area of a body which employs at least one trimetallic nitride template endohedral metallofullerene compound having at least one diagnostic atom and at least one treatment atom encapsulated within a fullerene cage such that the diagnostic atom is different from the treatment atom.
Another object of the present invention is to provide a method for imaging and treating an area of the body that is versatile and amenable to many different applications in a body.
The aforementioned objects were accomplished by the present invention which is directed toward a method for imaging and treating an area of a body. The method comprises the steps of providing at least one trimetallic nitride template endohedral metallofullerene compound. The metallofullerene compound has at least one diagnostic atom and at least one treatment atom encapsulated within a fullerene cage. The diagnostic atom is different from the treatment atom. The trimetallic nitride template endohedral metallofullerene compound is administered into a body and is traced to an area of the body. The treatment atom is then permitted to react in the area of the body. The novel feature of this invention is that it employs a mixed metal cluster encapsulated within the fullerene cage. Since at least two of the three metals are different from each other, it is possible to have both a diagnostic and a treatment atom contained within the same fullerene cage.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be obtained by means of instrumentalities in combinations particularly pointed out in the appended claims.